1. Field of the Invention
The present invention relates to a compression tray of the type used in a mammography apparatus, as well as to a method for the manufacture of such a compression tray and a mounting for such a compression tray.
2. Description of the Prior Art
In mammography, compression plates are used in order to place and to compress the female breast on the subject table for the x-ray acquisition. The breast should optimally be compressed with a uniform thickness. The material of the compression tray must be x-ray-resistant since the compression tray is located directly in the beam path. A uniform material thickness must be present in the irradiation region in order to avoid contrast fluctuations. It should be possible to remove the compression tray from the retainer without tools in order to clean and disinfect the compression tray.
Known compression trays made of PC (Lexan) are produced in a deep-draw method. For this the PC plate must be dried for a longer time in an oven in order to be able to be subsequently heated to the deformation temperature. The material can then be brought into a positive or negative deep-draw shape by the application of a vacuum. The wall thickness of the initial material is thereby reduced by up to 50%.
Very different wall thicknesses that become apparent in a contrast attenuation in the x-ray exposure are created by the deep-draw method. After the deep-draw process, the excess material must be mechanically removed. Extreme stresses are introduced in the material by the deep-draw process. PC is not resistant to alcohol-containing cleaning agents. Given their use, ultra-fine surface cracks are generated that can lead to a breakage of the compression tray. The known compression trays are mechanically rigidly connected with the mount and can only be removed with a tool. These require a mechanical connection part in order to transfer the compression force from the tray to the mount.